Enlargening the Sync Previous Days Option

There seems to be a limit on the previous days synced, you can't put in more than 60 days. Its not really practical because some people want to put their entire calendar starting from a year ago on to google calendar (I know I could put it from outlook but...
I don't use outlook so... only thunderbird). I am willing to patch this but I haven't been able to load the project for some reason and looking at previous posts I am unsure if the code checked in is the latest version.